Last week I worked on a seemingly simple, almost trivial problem – the mapping from IP addresses to country. Free services out there that return the full geographical location data given an IP address are well known. Some of them have API that could be called programmatically. Nothing out of ordinary; people were doing that for a long time. My problem was that I needed to do it fast and for a big data set, effectively adding a country to the stream of IP addresses coming from the online service. And I wanted to do it in R.